In an image forming apparatus, for example, an electrostatic latent image that is formed on a surface of a photosensitive drum is developed using a charged toner. In this case, when printing of a low print ratio continues, the potential of the toner rises more than necessary, and so-called scumming, a phenomenon in which toner is attached to a margin portion, may occur. Patent Document 1 discloses an image forming apparatus in which a decrease in image quality is prevented by discarding the toner in accordance with the print ratio.